1. Field of the Invention
The present invention relates to an auxiliary device for an electronic apparatus and, in particular, to an auxiliary device for an electronic apparatus which performs signal exchanges between it and the electronic apparatus.
2. Description of the Related Art
There has been proposed an auxiliary device for an electronic apparatus which is in the form of an adaptor called a station, which is used, when, for example, a portable electronic apparatus whose functions are limited to some extent for the sake of portability is used indoors. In such a case, the portable electronic apparatus is connected to the adaptor so that it may be endowed with the same functions as those of an installed-type electronic apparatus.
FIGS. 1 and 2 show an example of a connection mechanism used in such an adaptor serving as an auxiliary device for an electronic apparatus.
A slider a is slidably supported by a chassis (not shown). A coil spring b is stretched between the slider a and the chassis (not shown), whereby the slider a is biased to the right in FIG. 1, i.e., in the direction of an arrow A.
Engagement sections c are formed in the portion of the slider a which is near the left-hand end thereof as seen in FIG. 1. Further, in the right-hand end portion of the slider a, there is formed a cutout d which is laterally elongated and open at the right-hand end. In those side edge portions of the slider a which are nearer to the left-hand end thereof, cutouts are formed whose left-hand ends constitute abutting edges e. A cut-and-raised portion f is formed in the slider a at a position nearer to the right-hand end thereof, and a roller g is rotatably supported by this cut-and-raised portion f.
Substantially the central portion of a control member h consisting of a plate spring material is fastened to the chassis (not shown). A substantially reverse-L-shaped section protrudes to the left from substantially the central section of the laterally elongated portion of the control member h, that is, the left-hand side portion of the control member h is branched into two sections. A placement detecting shaft i is fixed to the right-hand end portion of the control member h so as to protrude upwards therefrom. The lower end portion of this placement detecting shaft i is formed as a large diameter section i1, and the portion extending upwards therefrom is formed as a small diameter section i2 whose outer diameter is smaller than that of the large diameter section i1. A head section i3 whose outer diameter is larger than that of the small diameter section i2 is formed on the small diameter section i2. The outer diameter of the small diameter section i2 is slightly smaller than the width of the cutout d of the slider a and the outer diameter of the large diameter section i1 is larger than the width of the cutout d.
The left-hand end portion of each arm of the branched portion is bent upwards to form stopper members j. Upwardly protruding placement detection protrusions k are provided on the left-hand end portions (FIGS. 1 and 2) of the outer side edges.
In the condition in which one apparatus is not placed on the placement surface of the other apparatus, for example, in the condition in which the portable electronic apparatus as mentioned above is not attached to the adaptor, the head section i3 of the placement detection shaft i protrudes upwards through a hole formed in the placement surface of a casing (not shown), and the upper end portions of the placement detection protrusions k protrude beyond the placement surface through holes formed in the placement surface. In this condition, the stopper members j of the control member are, as shown in FIG. 1, positioned on the right-hand side of the abutting edges e of the slider a, whereby the slider a is prevented from moving to the right (the direction indicated by the arrow A in FIG. 1). The position of the slider a in this condition is the non-engagement position. When the slider a is in the non-engagement position, the large diameter section i1 of the placement detection shaft i is at a height corresponding to the cutout d of the slider a and a shutter (not shown) supported by the slider a closes connector protrusion holes formed in the placement surface of the casing.
A laterally elongated connector support member l is supported by the chassis (not shown) at a position to the right from the center thereof so as to be vertically rotatable. A spring peg n protrudes downwards from the lower edge of the portion where the rotation fulcrum m of the connector support member 1 exists, and a coil spring o is stretched between the spring peg n and the chassis. As a result, as shown in FIG. 2, the connector support member l is biased so as to rotate such that the left-hand end portion thereof moves downwards. A protrusion p to be depressed, which protrudes upwards, is formed at the right-hand end of the connector support member l, and a movable connector q is arranged on the upper surface of the left-hand end portion thereof.
When an electronic apparatus r which constitutes one apparatus (Only a part of the casing thereof is shown in the drawing) is placed on a placement surface (not shown) of an adaptor which constitutes the other apparatus (At this time, the right-hand end portion of the bottom surface of the one apparatus r is abutted against the placement surface, and then the left-hand end portion is gradually caused to abut the placement surface), the head section i3 of the placement detection shaft i is first pushed in by the right-hand side bottom surface of the one electronic apparatus r, whereby the small diameter section i2 of the placement detection shaft i reaches a height corresponding to the cutout d of the slider a.
Since the placement detection protrusions k are depressed by the left-hand side bottom surface of the electronic apparatus r, each arm of the branched portion of the control member h is deflected such that the left-hand end thereof moves downward, that is, as shown in FIG. 2, elastically displaced from the position indicated by the solid line to the position indicated by the two-dot chain line, whereby the stoppers j move downward from the position indicated by the solid line in FIG. 2 to the position indicated by the two-dot chain line, and the engagement of the slider a with the abutment edges e is cancelled, so that the slider a moves to the right in the direction indicated by the arrow A of FIGS. 1 and 2 by the moving force due to the biasing of the coil spring b. At this time, the small diameter section i2 of the placement detection shaft i is inserted into the cutout d of the slider a, whereby the movement of the slider a to the right is permitted.
By this movement to the right of the slider a, the engagement sections c thereof engage with an engagement section (not shown) of the electronic apparatus r, and the shutter (not shown) supported by the slider a moves to thereby open a connector protrusion hole (not shown) formed in the placement surface.
At the same time, the roller g supported by the slider a pressurizes to the right (in the direction indicated by the arrow A of FIG. 2) the protrusion p to be depressed of the connector support member l, so that the connector support member l is rotated against the rotating force due to the coil spring o such that the left-hand end thereof is rotated upwards as indicated by the arrow B of FIG. 2, so that the movable connector q supported at the left-hand end thereof protrudes upwards through the connector protrusion hole (not shown) to be connected to a connector for connection (not shown) of the electronic apparatus r.
The above-described connection mechanism has a problem in that each section thereof may be brought into a halfway state by an erroneous operation.
That is, as described above, first, the placement detection shaft i is depressed and then the placement detection protrusions k are depressed, whereby the slider a moves to the right in the direction of the arrow A in FIG. 1, and the keeping of the placement of the electronic apparatus r on the placement surface and the connection of the movable connector q to the connector for connection are effected. However, if something goes wrong and the placement detection protrusions k are depressed first, the stoppers j move downward and the lock for the slider a is cancelled, so that the slider a moves to the right. However, since the placement detection shaft i is not depressed, the large diameter section ii of the placement detection shaft i is at a height corresponding to the cutout d of the slider a, so that the placement detection shaft i cannot enter the cutout d, with the result that the slider a stops, as indicated by the two-dot chain line of FIG. 2, when the right-hand side edge thereof abuts the large diameter section i1 of the placement detection shaft i. In this condition, the right-hand side edge of the slider a is in press contact with the placement detection shaft i due to the force of the coil spring b, so that this placement detection shaft i cannot be pushed down. As a result, the lock is effected in a halfway state in which the slider a is only slightly moved to the right.
Further, in the above-described connection mechanism, it is not possible to obtain a stable press-contact force for the connector for connection on the electronic apparatus r side and the movable connector q on the adaptor side.
That is, the press-contact force for the connector for connection and the movable connector q depends upon the spring force of the coil spring o which acts through the slider a and the connector support member l. However, since the coil spring o is stretched between the slider a and the chassis, the force which brings the movable connector q into press contact with the connector for connection varies depending upon the frictional resistance, etc. between the slider a and the chassis. In addition, the frictional resistance etc. between the slider a and the chassis greatly varies due to deformation, etc. of these components. As a result, it is difficult to obtain a press-contact force for the connector for connection and the movable connector as designed, and a marked deviation occurs due to contamination and deformation of the members as the apparatus ages.